On Tuesday, GE Aerospace announced on its social media channels that the General Electric GEnx engine had recently completed ground testing on 100% sustainable aviation fuel in collaboration with NASA. The engine is attached to a Boeing 787-10 Dreamliner jet, and the aero-engine manufacturer said testing was another step toward better understanding the qualities of SAF.Simple Flying has reached out to GE Aerospace to learn more about the tests and what the next steps will be but was yet to receive a response at the time of publication, and we will update this article as we learn more. Meanwhile, the engine is not the first that General Electric has run on 100% sustainable fuel. In May 2022, GE ran the Passport business jet engine, which entered service in 2018, on 100% SAF during a series of ground tests at its Peebles Test Operations in southern Ohio.In 2021, the CFM International (a joint partnership between GE Aerospace and Safran) LEAP 1B engine powered the first passenger flight with 100% SAF in one engine when United Airlines operated a Boeing 737 MAX from Chicago’s O’Hare to Washington’s Reagan National Airport with 115 people on board on December 1.The Boeing ecoDemonstrator Alaska Airlines 737-MAX 9 also tested 100% SAF in its LEAP 1B together with NASA in October of the same year, measuring engine particle and trace gas emissions over different thrust settings and comparing different percentage blends of SAF vs. Jet A fuel.

Which Dreamliner powerplant will be first?

The GEnx is GE Aerospace's fastest-selling widebody jet engine in the history of the company. It powers the Boeing 787 Dreamliner and the 747-8 and has sold in over 2,700 units. It is one of the options for the Dreamliner, along with rival Rolls-Royce's Trent 1000. General Electric has a commanding share of the 787 market with more than 60% of orders.

But perhaps there is now a little bit of healthy competition sparked by the fact that Rolls-Royce has committed to, along with Boeing and Virgin Atlantic, have a Dreamliner operating solely on 100% SAF across the Atlantic as soon as next year. Let's see who gets the prestigeful and groundbreaking "100% SAF certified" stamp from regulators first.

Will regulators be ready?

Of course, 100% SAF certification will most likely not come down to a single engine. Regulators will need to be satisfied that a pure sustainable aviation fuel blend will be entirely failsafe before increasing from the current 50% allowance. Results of all tests thus far are promising, and we are bound to see much more 100% SAF testing - as well as testing with different types of lower-carbon fuels - as the year progresses.

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Source: NASA Aeronautics Research Mission Directorate